Nowadays, industry and commerce have extremely developed so that cities have grown more and more crowded with people, who are forced to have less and less space for living owing to fast rising cost of land and houses. Besides, except weekends they cannot get rather long hours for enjoying leizure, exercise or sports. Therefore, this invention has been devided to furnish an easy means for a kind of exercise which does not need a large space but can be played at any time or place.